A conventional weapon control system uses a laser source for illuminating a target. The illuminated target is tracked by means of electronic video tracking circuits. A boresight for the weapon control system takes the form of a video display wherein the laser illuminated target is displayed in superposition with reticle cross hairs. The reticle is generated by a symbol generator in accordance with data received from the video tracker and represents the position of the laser beam within a scene.
A significant problem with this type of imaging system occurs when ambient influences, such as strong ambient magnetic fields causes a shifting of the image as picked up by a television camera which follows the illuminated target. This is due to the effect of the magnetic fields on the deflection circuits of the camera. Since reticle generation is not affected by these fields, the reticle will not appear in superposition over an illuminated target, although in reality it should do so. Accordingly, line-of-sight errors become manifest to a weapon control operator.
Accordingly, there is a great need for compensating for the displaced erroneous movement of a target or image due to these extraneous environmental factors, such as strong magnetic fields.